For example, Patent Literature 1 discloses a driving operation assisting device (pedal reactive force controller) configured: to calculate risk potential for the drive by the driver; and to convey the calculated risk potential to the driver in the form of both accelerator pedal reaction force (an amount of stimulus) and visual information.
The driving operation assisting device disclosed in Patent Literature 1 is capable of conveying the risk potential in excess of a predetermined maximum value to the driver in the form of the visual information (e.g., a flashing symbol for a preceding vehicle) to be displayed on a display monitor (see FIG. 34). Otherwise, the driving operation assisting device is capable of conveying the risk potential in excess of a predetermined maximum value to the driver in the form of the visual information represented by a graph showing changes in the risk potential (see FIG. 40).
The driving operation assisting device disclosed in Patent Literature 1 is capable of assisting the driver in accurately grasping conditions around his/her own vehicle by showing the driver how large the risk potential is, and how the risk potential is changing, in the form of the visual information in addition to the accelerator pedal reaction force (the amount of stimulus) in the above-described manner.